Aging status characterization of Chinese rice wine based on key aging-marker profiles combined with principal components analysis and partial least-squares regression

The “key aging-markers” were a kind of potential “aging markers” with a high odor activity value (OAV) or flavor dilution (FD) value, and this study aimed to characterize their aging scents in classifying the aging status of Chinese rice wine by the assessment of OAV values, principal components analysis (PCA) and partial least-squares regression (PLSR). Finally, a total of 29 “key aging-markers” were extracted in 0–15 years-aged rice wines, and a combined result showed that (1) sulfides, 4-vinylguaiacol (4-VG) and 4-ethylguaiacol (4-EG) with the typical sulfur, clove and spicy smells distinguished the 0Y-ageds from others, and the nail polish and solvent smells from alcohols were also worth-considered; (2) in “post-aging” period (1–2 aged-years), the flavored contributions of alcohols, acetic acid, ethyl octanoate and isoamyl acetate were emphasized by their statistical roles. Meanwhile, the key aging-markers with the fruity, sweet and floral increased, and the phenolic and oxidized markers appeared; (3) the aging aroma in “aging/storing” period (3–5 aged-years) became stronger, especially the cinnamon-like from cinnamaldehyde, trans-cinnamic acid and ethyl cinnamate. Meanwhile, the typical long-aging characteristics from sotolon, guaiacol and γ-decalactone appeared; (4) the period of 10–15 aged-years was a complex collection, and the typical caramel-like from furans differentiated from others, following by the fruity, floral and honey smell from esters and aromatics with benzene. Moreover, the uptrends of acids, aldehydes and ketones made the fragrance thicker. Therefore, this result suggested that the aging status characterizations of 29 “key aging-markers” enable the age discrimination of Chinese rice wine by aging scent.